There are various situations in which it is desirable to detect the presence of radiation. For example, a nation may wish to detect illicit radioactive material that is entering or leaving its borders because the radioactive material could pose a health and/or national security risk. Small, low-power radiation detectors are desired to aid border personnel in detecting the radioactive material. As the size and power requirements decrease, the ability of the border personnel to use the detector in varied situations increases. For example, a small hand-held detector could be used to facilitate the detection of illicit radioactive material at non-authorized border crossing locations since the small size makes the hand-held detector more portable than a larger radiation detector. Additionally, small, portable hand-held detectors could be used to inspect cargo without having to unload all the cargo and transport it to a larger detector.
However, decreasing the size and power requirements of a detector can also affect the sensitivity of the detector. For example, solid state germanium detectors have good sensitivity to radiation. However, germanium detectors typically require cooling, such as with liquid nitrogen. This requirement makes germanium detectors less practical for portable applications. Solid state silicon detectors typically require no cooling and are, thus, better-suited for small portable applications. However, silicon detectors are typically less efficient in sensing radiation than germanium detectors.